Injection blow molding process

ABSTRACT

A process and multistation apparatus for injection blow molding a thermoplastic material to form a blow molded container having an integral injection molded handle is disclosed. The process and apparatus feature an injection mold which is closed to form an injection mold cavity with a contiguous injection mold handle cavity. A preform pin is inserted into the injection mold cavity through a preform carrier to form a preform recess into which hot thermoplastic is injected to form a hollow preform having a solid injection molded handle. After cooling the thermoplastic preform the preform pin is withdrawn and the molds are opened. The injection formed preform may be optionally heat treated prior to the preform being enclosed within a blow mold. The blow mold forms a cavity having the final desired container shape and a cavity into which the handle is enclosed. Blow air is introduced into the preform to inflate it to the shape of the blow mold cavity thereby forming a blow molded container having an injection molded handle attached thereto. A preform carrier may be used to carry the injection molded preform from the injection mold station to the blow mold station. The carrier attains attachment to the preform as the preform is formed in the injection mold.

This is a division of application Ser. No. 71,301, filed Aug. 30, 1979,now U.S. Pat. No. 4,280,805.

BACKGROUND OF THE INVENTION

The popularity of blow molded handleware has grown in recent years asconsumers begin to appreciate the ease of use and the non-breakablecharacteristics of such containers. Handled containers are especiallypopular in the larger sizes, i.e. containers having a capacity of onequart or greater. Exemplary of products which are often packaged inhandleware are starch, bleach, detergent, milk, distilled water, etc.

In the past a class of blow molding machines known as the "inject,extrude and blow" machines have been adapted to blow mold handledcontainers of large size. In these machines the neck, or finish, of thecontainer is injection molded in an injection mold superimposed on anannular orifice. After the mold is filled from the orifice, the mold ismoved away from the orifice as the tube integral with the materialfilling the mold is extruded through the orifice. The blow mold is thenclosed between the tube and the neck mold of the orifice pinching thetube shut near the orifice. Blow air is then injected through the neckmold into the tube, and the tube is simply inflated to the configurationof the blow mold. In early attempts to adopt such injection, extrude andblow machines for the manufacture of handled containers, it was foundnearly impossible to extrude a tube having both an integral injectionfinish and a diameter sufficient to provide material properly located inthe parison to be pinched shut by the blow mold to form an integralhandle upon blowing. This early attempt at forming handleware resultedin the production of much waste material, i.e. flash, which wasprincipally found on the interior and exterior of the handle. Otherproblems were also recognized, such as uneven material distribution andpin holes in the handle.

Further refinements were made on the inject, extrude and blow processwhich were claimed to reduce the amount of flash produced and to alsoprovide a container having uniform material distribution. By reducingthe amount of flash which must be trimmed from the container, leaks inthe container are said to be avoided. Exemplary of these newer machinesis the one disclosed in U.S. Pat. No. 3,944,642.

In the newer version the tubular parison integral with the injectionmolded finish portion of the container is formed in a conventionalmanner as set forth in U.S. Pat. No. 3,008,192. The preform is thenpreblown in an intermediate blow mold which has a similar but smallershape than the final blow mold. The preblow preform has a portion whichis of a configuration such that the preform portion which will form thehandle will be encompassed within the handle defining portions of thefinal blow mold. Once the preblown preform is positioned within thefinal blow mold the preform is blown to its final shape. Even thoughthis machine and process produces a handled container which is free ofexternal flash, there is still produced flash which is in the interiorof the handle, i.e. in the space encompassed between the handle and thecontainer.

Handleware may be produced without concurrent production of flash by theapparatus disclosed in U.S. Pat. No. 3,029,471. This apparatus injectionforms the handle followed by formation of an extruded tube which isintegral with the handle. The tube is extruded to a sufficient length tofill the axial length of an adjacent split blow mold. The split blowmold is closed to capture that portion of the extruded tube beneath theinjection molded handle so that that portion of the tube may be inflatedto form the container. Since the apparatus passes the moltenthermoplastic material through a single orifice for both the injectionand extrusion steps, a highly complex timing and mechanical system mustbe used. Furthermore, temperature control of the injection finish withrespect to the extruded tube will be difficult to handle at best.

Therefore it is an oblect of this invention to provide a process andapparatus for forming handleware which is free of undesirable flashformation and which is the paragon of simplicity.

It is a further object of this invention to provide an apparatus andprocess which is capable not only of forming flashless handleware, butwhich is also capable of forming biaxially oriented handleware.

THE INVENTION

A multistation apparatus for injection blow molding a thermoplasticmaterial to form a blow molded container having an integral injectionmolded handle, said apparatus comprising: an injection molding station,for forming a plastic preform having an integral handle thereon, themolding station including, (i) a split injection mold defining a preformcavity with a contiguous injection molded handle cavity, an injectionmold carrier cavity, and an injection nozzle cavity, the preform cavitybeing between the injection mold cavity and the nozzle cavity, (ii)power means engaged with the split injection mold for opening andclosing the split injection mold, (iii) a movable preform pin, (iv) aninjection nozzle which nests into the injection nozzle cavity when thesplit injection mold is closed, and (v) injection power means forinjecting, under pressure, thermoplastic material through the injectionnozzle to a preform recess formed at least partially by said injectionmold handle cavity and by the preform pin being positioned within thepreform cavity; a blow molding station having, (i) a split blow molddefining a blow mold cavity with a contiguous blow mold handle cavityand a blow mold carrier cavity, (ii) power means engaged with the splitblow mold for opening and closing the split blow mold, and (iii) amovable blow pin, the blow pin supplying pressurized gas to inflate thepreform; moving means for moving a preform carrier from station tostation, the preform carrier having a portion to achieve attachment ofthe preform to the preform carrier when the preform is formed by theinjection of thermoplastic material in the preform recess and havinganother portion which is in mounted relationship with the moving meansat the time the attachment is achieved, and the preform carrier being(i) receivable into the injection mold carrier cavity and the blow moldcarrier cavity, and (ii) hollow to allow passage through the preformcarrier of the preform pin and to allow nesting of the blow pin in thepreform carrier.

Optionally there may be provided heat treating stations between theinjection molding station and the blow molding station. These heattreating stations would be utilized to either raise, lower or maintainthe temperature of the preform as it moves from the injection moldingstation to the blow molding station. The heat treating stations can alsobe utilized to selectively heat or cool a specific portion of thepreform to provide a heat programmed preform to the blow moldingstation.

Since the preform is rigidly held by the moving apparatus as it is movedfrom the injection molding station through the heat treatment stationsto the blow mold station, the exact location of any point on the preformis known. Locating the injection formed handle within the blow moldhandle cavity is therefore easily achieved.

The apparatus of this invention is also highly advantageous in that itis readily adaptable for producing biaxially oriented containers. Whenbiaxial orientation is desired the optional heat treating stations areused to maintain or bring the injection molded preform to its biaxialorientation temperature and the blow molding station is provided with ameans for biaxially orienting the container with longitudinal and radialstretch.

To increase cycle speed and to provide economy in manufacture, theapparatus of this invention may also be provided with an ejection systemfor removing the formed container from the moving apparatus. Such asystem would be located subsequent to the blow molding step and prior tothe injection molding step.

These and other features of this invention contributing satisfaction inuse and economy in manufacture will be more fully understood from thefollowing description of a preferred embodiment of this invention whentaken in connection with the accompanying drawings wherein identicalnumerals refer to identical parts and in which:

FIG. 1 is a top plan view of an embodiment of this invention;

FIG. 2 is a front elevational view of the injection molding stationshown in FIG. 1;

FIG. 3 is a sectional view taken through section lines 3--3 of FIG. 2;

FIGS. 4-6 are side partial sectional views taken through the center lineof the split injection mold shown in FIG. 2;

FIG. 6A is a broken away front view of the split injection mold shown inFIG. 2;

FIG. 6B is a side view of the split injection mold shown in FIG. 2;

FIG. 7 is a sectional view taken through section lines 7--7 of FIG. 6;

FIG. 7A is a sectional view taken through section lines 7a--7a of FIG.4;

FIG. 8 is a front elevational view of one of the heating stations shownin FIG. 1 with the heating station in the down position;

FIG. 9 is a front elevational view of the heating station shown in FIG.8 in the up position;

FIG. 10 is a sectional view taken through section lines 10--10 of FIG.8;

FIG. 11 is a front elevational view of another heating station shown inFIG. 1;

FIG. 12 is a front elevational view of the blow molding station shown inFIG. 1;

FIG. 13 is a sectional view taken through section lines 13--13 of FIG.12;

FIGS. 14-16 are front partial sectional views taken through the centeraxis of split blow mold shown in FIG. 12;

FIG. 17 is a side elevational view of the ejection system shown in FIG.1;

FIG. 18 is a front elevational view of the ejection system shown in FIG.17; and

FIG. 19 is a perspective view of a portion of the moving means shown inFIG. 1 and the attaching mechanism shown in FIG. 1.

Referring now to FIG. 1, there is shown an apparatus of this inventiongenerally designated by the numeral 10 which apparatus includes aninjection molding station, generally designated by the numeral 12, afirst heating station, generally designated by the numeral 14, a secondheating station, generally designated by the numeral 16, a blow moldingstation generally designated by the numeral 18, and an ejection orremoval station, generally designated by the numeral 20. These variousstations are positioned around a moving apparatus generally designatedby the numeral 22 which includes a rotating table 600 and an attachingmechanism, generally designated by the numeral 11 for holding theinjection formed preform as it moves through the various stations. Theutilization of the first and second heating stations 14 and 16 areoptional. In some instances it may be desired that instead of twoheating stations, a heating and cooling station be utilized incombination. Depending upon the particular thermoplastic material beingworked and upon the requirements needed for the blow molding of thismaterial, it may be desirable not to utilize any heat treatment stationswhich use positive heat addition or removal. In these instances thepreform would be subject only to ambient air. The particular combinationof heat treatment stations, or the lack of them, is fully within thediscretion of the user of the apparatus of this invention and theaddition or deletion of such stations would not materially affect theoperation of this apparatus.

Blow molding station 18, for the apparatus in the drawings, can be usedfor the formation of biaxially oriented containers. As shown in FIGS.14-16, a push rod may be utilized to guide the preform as it is blown toachieve simultaneous axial and radial stretch. It is to be understoodthat the blow molding station may also provide conventional blow moldingwithout the utilization of a stretch rod.

The injection molding station 12 is shown in FIGS. 2 and 3. As can beseen from these figures, injection station 12 has a frame which includesa floor plate 110 and injection molding side plates 108 and 106.Connecting injection molding side plates 108 and 106 at a point neartheir mid height is horizontal tying plate 130. At the upper end ofinjection molding side plates 108 and 106 there are a pair of uppertying plates 118 which provide tying of plates 108 and 106 together atthat point.

The split injection mold is defined by complementary cavities in theinjection split mold halves 111 and 111a. The embodiment illustrated hasan injection split mold which defines two preform cavities. It is to beunderstood however, that single cavity operations or operationsinvolving more than two cavities are possible with the apparatus of thisinvention. To produce the handleware of this invention the splitinjection molds have a cavity defining a main body portion, i.e. preformcavity, and a handle portion as seen in FIG. 6A. Preform pin 124 fitswithin the preform cavity to produce a closed end hollow preform. Thehandle cavity is injection filled with thermoplastic material to producethe handle which is designated "H" in the drawings.

Injection split mold halves 111 and 111a are mounted, respectively, onplates 114 and 117. Platen 114 is a non-moving platen with platen 117being movable in a horizontal direction. Movement is achieved by theutilization of a bank of hydraulic cylinders 150, 151, and 152 which areshown in FIG. 1. These hydraulic cylinders are mounted to horizontaltying plate 130. To insure aligned movement of platen 117 in thehorizontal direction there is provided a plurality of guide rods. One ofthese guide rods is shown in FIG. 3 and is labeled with the number 160.Guide rod 160 is typical of the other guide rods utilized and thedescription of it would apply to the other guide rods utilized. Guiderod 160 is rigidly attached to platen 114 at one of its ends and to stud169 at its other end with stud 169 in turn being attached to theunderside of horizontal tying plate 130. Note, as is shown in FIG. 3,guide rod 160 passes through an aperture in platen 117. The fit of guiderod 160 through this aperture must be, of course, exact to insurefidelity of movement of platen 117.

Positioned immediately below injection split mold halves 111 and 111aand centered to the two preform cavities are two injection nozzles, onefor each cavity. Only one of these nozzles is shown in the drawings,however a description of it is equally applicable to the other.Injection nozzle 161 is positioned so that it enters into an injectionnozzle cavity provided in injection split mold halves 111 and 111a.Upward and downward movement of injection nozzle 161 is provided so thatit may move upward into the injection nozzle cavity and may movedownward away from the cavity. Injection nozzle 161 is mounted to tyingbeam 112. Note that in FIG. 1 the injection apparatus utilized to injectthe plastic through the injection nozzle is positioned adjacent toinjection molding station 12 and is labeled "I." The position andconstruction of apparatus "I" is discretionary with the user of theapparatus of this invention, it being understood that any apparatuswhich is capable of injecting hot thermoplastic material under pressurethrough the injection nozzles into the injection mold preform recesses,hereinafter described, will be suitable for the purposes of thisinvention. Immediately above injection split mold halves 111 and 111athere is positioned a pair of preform pins 124 and 124a. Preform pins124 and 124a are mounted rigidly to preform mounting stud 129. Preformmounting stud 129 can be bolted to block 128 so that easy replacement ofpreform pins 124 and 124a can be achieved by the mere unbolting of stud129 from block 128. On the upper surface of block 128 there are attachedthree double acting hydraulic cylinders 116. These cylinders willprovide upward and downward motion to pins 124 and 124a so that they mayenter the split injection mold and be removed therefrom when desired. Toinsure perfect alignment of preform pins 124 and 124a within splitinjection molds during the movement provided by hydraulic cylinders 116there is provided a pair of gear tracks 120 and 120a which are connectedto injection molding side plates 108 and 106, respectively. These geartracks cooperate with circular gears 122 and 121 to provide positivemovement and thus assure correct alignment. Circular gears 122 and 121are rotatively mounted to gear axles 122a and 121a, which are in turncarried by block 128.

Located adjacent the bottom of the injection split mold half 111 are twomechanisms for severing the injection tails from each of the preformsformed in the two preform cavities. These mechanisms are optional andmay not be used in those cases where the downward movement of theinjection nozzle breaks the tail from the preforms. The severingmechanisms are identical and the description of one is equallyapplicable to the other. In FIGS. 6, 7 and 7A there is shown a severingmechanism generally designated by the numeral 180. As can be seen, thismechanism fits within a recess cut into the bottom of split injectionmold 111. Severing mechanism 180 has a block portion 166 with arms 166aand 166b. Mounted on the outside surfaces of arms 166a and 166b are pushrods 165 and 164, respectively. Positioned on the rear surface of arms166a and 166b are springs 167 and 168, respectively. Knife 162 ismounted on the front side of block 166 and as can be seen in FIGS. 6 and7A, knife 162 has a cupped surface 163 which is contoured so that itforms a portion of the injection mold cavity in injection split moldhalf 111. The leading edge of cupped surface 163 is a knife edge 190which is sharpened to achieve the severing of the injection tail. InFIG. 7A severing mechanism 180 is shown in the retracted position withcupped surface 163 forming a portion of the cavity in injection splitmold half 111. In FIG. 7 severance mechanism 180 is shown in theextended position. As can be appreciated, knife edge 190 has travelled apath which will enable it to sever a tail formed in the injection nozzlecavity. This severing action is depicted in FIG. 5 wherein severingmechanism 180 is in the extended position.

As mentioned previously, injection molding station 12 is positionedaround moving apparatus 22. Moving apparatus 22 includes a rotatingtable 600 and a plurality of attaching mechanisms 11 which are spacedequiangularly about table 600. For the embodiment shown, table 600rotates in a counter-clockwise direction. Rotation is an interruptedmovement with the table stopping rotation when the preform or bottle isregistered before a station. Interrupted rotation is provided by any oneof the many well-known commercial conventional systems.

The attaching mechanism is attached to the injection molded preform asit is formed at the injection molding station 12. The mechanism thencarries same to subsequent stations until the final blown article isremoved from mechanism 11 at the ejection or removal station 20. Theattaching mechanisms 11 shown in FIGS. 1 and 19 are especially adaptedfor utilization with the illustrated embodiment of this invention. It isto be understood that other attaching mechanisms may be utilized toaccommodate the peculiarities of other systems of this invention. It isalso obvious that while a rotating table may have advantages withrespect to conserving floor space, other moving apparatuses may be usedhaving different configurations. For example, the moving apparatus mayprovide linear movement of the attaching mechanisms with the variousstations positioned adjacent thereto in a line.

Reference is directed to FIG. 19 wherein a detail blowup of one of theattaching mechanisms is depicted. Since all of the attaching mechanismsare essentially identical, a description of any one mechanism is equallyapplicable to all.

As is shown in FIG. 19, attaching mechanism 11 is movably mounted totable 600 by means of left mounts 602a and 602b and right mounts 602 and602c. Movably held by these mounts are attaching mechanism rods 604 and604a. At the proximate ends of these rods there are rod stops (notshown) to limit the outward travel of the rods. At the distal end ofrods 604a and 604 there is attached thereto plate 608. Between plate 608and mounts 602b and 602c there is provided, around the rods, springs606a and 606 which urge the rods, with attached plate 608, in adirection outward from the center of table 600.

Plate 608 has a pair of open-ended pockets for receipt of a pair ofmandrels 24 and 24a to which the preforms are held as they travel fromthe injection molding station to the remaining stations. In FIG. 19 oneof the two identical pockets is shown and a description of it is equallyapplicable to the other pocket. The exposed pocket in FIG. 19 is shownto have a circular aperture therethrough defined by annular sidewall616. Immediately above annular sidewall 616 is landing area 610 which isdimensioned to receive flange portion 612 of mandrel 24. Assuringfurther that there is no excess wobble of mandrel 24 within its pocketthere is provided annular mandrel wall 614 which is dimensioned to nestwithin the aperture defined by annular sidewall 616. Below annularmandrel wall 614 there is provided a pair of intersecting beveledsurfaces 618 and 620. These surfaces resemble two truncated cones whichintersect at their bases and are received in complementary beveledcavities found in the injection split mold and the blow split mold ashereinafter described. By utilizing beveled surfaces 618 and 620,fidelity of positioning within the injection and blow mold cavities isachieved when the injection split molds and the blow split molds closearound a portion of mandrel 24. With the mandrels captured in theinjection split mold, as shown in FIG. 4, each mandrel has an annulardownward facing surface 621 which will form the uppermost boundary ofthe recess into which the thermoplastic material is to be injected whenthe preform pins are in place. Immediately below surface 621 is amandrel end piece 622 which will hold the injection formed preform atits neck subsequent to the injection molding operation. Another functionserved by surface 621 is that it, in combination with the preform pin,forms the inside boundary of the injection mold recess.

The mandrels described above are ones which have been found to be highlypreferred. They also reflect the finding that it is highly preferentialto carry the injection formed preform by its neck as it moves fromstation to station. However, other mandrels having different designswhich accomplish the same function as the above-described mandrels may,of course, be utilized. Furthermore, it may be desirable, in some cases,for the preform to be carried at a point other than at a point adjacentto the neck portion. For example, a mandrel could be used whereby thepreform is carried at a point near its midsection. Also it should berealized that while the mandrels described above carry the preform bymaking contact with it on its inside surfaces, it is fully within thescope of this invention to utilize mandrels which carry the preform bymaking contact on the preform outside surfaces. For the embodimentshown, the preform is held to the mandrel due to the preform contractingaround the mandrel and piece 621 as the preform cools. In those caseswhere the mandrel would capture the preform at a point on the preform'souterside surfaces, it would be desirable to utilize an interference fitto hold the preform to the mandrel.

The operation of the injection molding station 12 is initiated with theinjection split mold in the open position as is shown in FIG. 3. Table600 rotates and stops so that the mandrels 24 and 24a are positioned forreceipt by the injection split mold when it closes, as is shown in FIG.4. As injection split mold half 111a moves to close the split mold itwill press against a portion of the beveled surface of mandrel 24 and24a urging attaching mechanism 11 towards the center of table 600. Alsoas mold half 111a closes, it presses against push rods 164 and 165thereby retracting severing mechanism 180. The position of severingmechanism 180 in the retracted position is shown in FIG. 7A. Afterinjection split mold half 111a has completed its travel then the preformpins 124 and 124a are lowered through mandrels 24 and 24a and down intothe preform cavity formed by the injection split molds, cupped surface161 and annular downward facing surface 621. Note that the beveledsurfaces of mandrels 24a are nested into the complementary beveledcavities 80 and 80a which are so labeled in FIG. 6. This nesting, asnoted before, is to insure correct registration of the mandrel withrespect to the injection split mold cavity formed by the injection splitmold halves. FIG. 4 shows the injection split molds in the closedposition with the preform pins positioned in the cavity and theinjection nozzle cavity 196 (FIG. 5) enclosing nozzle 161. Plastic isinjected through the injection nozzle into the recess formed by theinjection mold cavities, cupped surface 163, the preform pin and theannular downward facing surface 621. Plastic will also enter injectionmold handle cavity 198 shown filled with plastic in FIG. 6A. From FIG.6A it is seen that the plastic flows from the recess to fill handlecavity 198. Subsequent to the injection of the hot thermoplasticmaterial into the recess and handle cavity, cooling fluid is passedthrough cooling traces 115 and 115a to cool the mold and thus chill theplastic. After the plastic has chilled sufficiently the preform pins 124and 124a are removed from the preform. To conserve cycle time, thepreform pins are withdrawn from the preform when the preform has reacheda temperature that renders the preform rigid enough to preventdeformation as the pins are removed. Also by pulling the pins withoutwaiting for further cooling, an energy saving is realized as the preformdoes not have to be heated back up to its blow molding or biaxialorientation temperature as the case may be. After the preform pins havebeen removed injection split mold half 111a is retracted. Follower rods164 and 165, due to the urging of follower rod springs 168 and 167,follow mold half 111a as it opens. This results in knife edge 190 movingacross the injection mold tail to sever it from preform "P." Thissevering operation is depicted in FIG. 5. As injection split mold half111a moves, attaching mechanism 111 will follow for a part of the totaltravel of the mold half. FIG. 5 shows this movement. The advantagegained by having attaching mechanism 11 move outwardly is that thepreform will be spaced sufficiently far enough from the split moldhalves so it can be rotated from the injection molding station 12without interference being encountered. Distance from split mold half111a is achieved as the travel of attaching mechanism 11 is stopped byrod stops while split mold half 111a continues to travel. Since preform"P" is rigidly held by mandrel 24a as it moves from station to stationevery point on preform "P" is easily determined at the subsequentstations. By having the ability to determine the exact location of everypoint on the preform it will be possible to perform very exact heatprogramming techniques on the preform which techniques would not bepossible if the preform moved with respect to the moving apparatus.

Depending upon the temperature of the preform as it leaves the injectionmolding station, the preform may either be sent immediately to the blowmolding station or to heat conditioning stations for treatment prior toreaching the blow molding station. If the preform is at a temperatureabove the desired temperature for the blowing procedure then the preformcan first be sent to a heat conditioning station in which the preform iscooled to the proper temperature. The converse is true if the preform isto cool. Also the preform can be heat programmed at the heatconditioning station. When heat programming is utilized, one portion ofthe preform will be heated or cooled to a different extent than otherportions of the preform. By having differences in heat contentthroughout the preform it is possible to control the extent and rate ofstretch at the blow molding station. As before mentioned, since thepreforms are held rigidly by the mandrels 24 and 24a it is possible, atthe heat treating stations, to apply heat or apply cooling to anydesired point on the preform with complete assurance that thisparticular point will be in perfect orientation when it reaches the blowmold station.

In FIGS. 8-10 there is shown a heating station of this invention,generally designated by the numeral 14. Heating station 14 has sideplates 204 and 214 which are tied together at their bottom by tying bar202. Also connecting side plates 204 and 214 is mounting plate 206.Mounting plate 206 has attached to its front face double actinghydraulic cylinder 208 which is connected to heating element pedestal210. Hydraulic cylinder 208 will provide the power for raising andlowering heating element pedestal 210. To aid in assuring that pedestal210 travels in a perpendicular direction to the horizon there areprovided guide rods 216 and 216a which are attached to the underside ofpedestal 210. Guide rods 216 and 216a pass through guide collars 218 and218a, respectively, which collars are attached to mounting plate 206.Heating elements 212 and 212a are attached to heating element pedestal210 by means of bolts 234 and 234a and plates 254, 250, 254a and 250a inthe manner shown in FIGS. 8, 9 and 10.

Heating elements 212 and 212a can be any type of heating element capableof supplying heat to preforms "P." Preferentially heating elements 212and 212a will be banks of electrical heating coils. As mentionedpreviously, it may be desirable to cool preforms "P" prior to theirarrival at the blow molding station. If this is the case, then heatingelements 212 and 212a would be replaced with cooling elements whichmight comprise hollow collars with forced air being blown therethroughonto the preform.

In operation heating station 14 is the paragon of simplicity. Preforms"P" are brought into position above first heating station 14 from theinjection molding station 12. Once the preforms have come to a full stopdouble acting hydraulic cylinder 208 is activated to raise heatingelements 212 and 212a so that they each surround their respectivepreform "P." The heating elements are held in this position as long asneeded to achieve the degree of heating desired. After preforms "P" havereached the desired heat level double acting hydraulic cylinder 208lowers the heating elements from around the preforms. The loweredposition is shown in FIG. 8 while the fully raised position is shown inFIG. 9. After the heating elements have been brought to the loweredposition, the preforms are free to continue their movement towardssecond heating station 16 upon rotation of table 600.

In FIG. 11 there is depicted a second heating station 16. This heatingstation is typical of one which may be utilized to heat program thepreform. Note that the heating elements 330 and 330a only surround theupper portion of the preforms "P" to provide selective heating. Theseheating elements may be of the same type used at station 14, i.e.,electrical heating coils. Second heating station 16 has two side plates304 and 314 which are tied at their bottom by tying bar 302. Alsoconnecting side plates 304 and 314 together is mounting plate 306.Attached to mounting plate 306 is double acting hydraulic cylinder 308which is connected to heating element pedestal 310. Guide rods 316 and316a which are attached to the underside of heating pedestal 310 passthrough guide collars 318 and 318a which collars are attached tomounting plate 306. Double acting hydraulic cylinder 308 is utilized toraise and lower heating element pedestal 310 while guide rods 316 and316a, in conjunction with guide collars 318 and 318a, assureperpendicular motion of heating element pedestal 310. Heating elements330 and 330a are mounted to heat element plates 332 and 332a,respectively, with these plates being secured by bolts 334 and 334a. Asis the case with first heating station 14, the preforms "P" are broughtinto position above heating elements 330 and 330a with the heatingelement pedestal 310 in the lowered position. Once preforms "P" are inposition, double acting pneumatic cylinder 308 raises heating elementpedestal 310 so that heating elements 330 and 330a are in properposition around preforms "P." After the necessary heating has beenaccomplished double acting hydraulic cylinder 308 is activated to lowerheating pedestal 310 thus removing heating elements 330 and 330a fromaround preforms "P" so that these preforms may be sent to the nextstation without interference with the heating elements.

As is the case with station 14, station 16 can be used to cool thepreforms "P" or alternatively, it may be used to apply heatlongitudinally to two sides of the preform with strip heaters therebyheat programming the preform so that it may be blown to a containerwhich is elliptical in cross section and so that the container hasimproved uniformity of wall thickness.

As can be seen in FIG. 1, there is provided space for an additionalstation between second heating station 16 and blow molding station 18.An additional heating or cooling station may be utilized at this pointas the need arises.

After the preforms have been heat treated they are in condition forreceipt by the blow molding station 18. As mentioned previously, blowmolding station 18 may be one in which the heat treated preforms areblown without biaxial orientation or with biaxial orientation. Thestation depicted in FIGS. 12-16 is one in which either type of blowforming of the container can be practiced.

Blow molding station 18 has a frame which includes side plates 412 and412a which are connected to floor plate 414 at their lower ends. Alsotying side plates 412 and 412a together are mounting stud 418, uppermounting plate 420 and lower mounting plate 416. Lower mounting plate416 has, at its end closest to table 600, front platen 422 which isrigidly attached thereto. At its other end, lower mounting plate 416 hasrigidly attached thereto bracket 434. Connecting front platen 422 withbracket 434 are blow molding guide rods 424 and 424a. These rods passthrough guide sleeves which are made a part of rear platen 430. One ofthe guide sleeves, guide sleeve 432, is shown in FIG. 13 and isidentical to the guide sleeve around blow molding guide rod 424.Connected to the inside face of front platen 422 is a split blow moldhalf 410. Connected to the inside face of back platen 430 is the othersplit blow mold half 408. Each of these halves has a pair of cavitiescut therein which cavities together form a pair of blow mold cavitiesfor blow forming the preform to yield the final container. The number ofcavities found in the blow split molds should correspond to the numberof preforms which will arrive at the blow molding station. As shown inFIGS. 14 and 15, the blow mold cavities, "C," define the shape of thebottle to which the preform is blown. In addition, each cavity hascontiguous therewith a handle cavity "HC." Handle cavity "HC" is largerthan handle "H" so that handle "H" has room to move as preform "P" isblown. This movement is illustrated sequentially in FIGS. 14-16. In FIG.14 handle "H" is at its nearest point to the center axis of preform "P."As preform "P" expands, handle "H" moves outwardly as seen in FIG. 15.Handle cavity "HC" is of a size to let handle "H" move withoutinterference throughout the blow cycle as is shown in FIG. 16 whereinhandle "H" has moved to its fartherest extent. Handle cavity "HC" doesnot need to be larger than handle "H" if, due to inflation, handle "H"does not move. This latter case would arise, for example, if the bottleneck was the same diameter as the preform.

Horizontal movement of split mold half 408 is accomplished by theutilization of double acting hydraulic cylinder 436 which is mounted toupper mounting plate 420 and the outside face of rear platen 430. Byhaving rear platen 430 slidably mounted to blow mold guide rods 424 and424a true horizontal movement of split blow mold half 408 is achievedfor perfect matching with split blow mold half 410.

Above the two cavities defined by split blow mold halves 408 and 410 areblow pins 428 and 428a. These blow pins are provided with verticalmovement so that they may enter into the hollow portion of the mandrelswhich are a part of attaching mechanism 11. This vertical motion is madepossible by way of double acting hydraulic cylinders 426 and 426a.Double acting hydraulic cylinders 426 and 426a also provide the powerrequired to raise and lower stretch rod 429 which is shown in FIGS.14-16.

FIGS. 14-16 depict blowing of bottle "B" from preform "P." In operation,the table rotates and stops with the preforms being positioned betweensplit blow mold halves 408 and 410. Split blow mold half 408 is movedforward towards the table to close the split blow molds and, in thistravel, engages a portion of beveled surfaces 618 and 620 within theblow mold carrier cavity thereby pushing attaching mechanism 11 untilsplit blow mold halves 410 and 408 completely encircle beveled surfaces618 and 620. The handled preforms are now centered and positioned withinthe cavity formed by the split blow mold halves. Next, blow pin 428 isintroduced through the opening end of mandrel 24 and seated therein.Once blow pin 428 has been seated, stretch rod 429 is lowered until itmakes contact with the bottom of the preform. Once contact has beenmade, blow fluid is introduced through blow pin 428 to begin inflationof preform "P." Simultaneously stretch rod 429 moves towards the bottomof the cavity formed by split blow mold halves 410 and 408 as is shownin FIG. 15. Simultaneous axial and radial stretch results in thecontainer being biaxially oriented and blown to conform to the blow moldcavity as is shown in FIG. 16.

The operation of blow pin 428a is identical to the operation of blow pin428 and thus the description of the latter blow pin operation is equallyapplicable to the former blow pin.

Once the preform has been blown to form bottle "B" cooling fluid ispassed through cooling traces 431 and 431a to cool the blown container.Once sufficient cooling has been achieved to insure that the containeris rigid enough so that support from the blow mold cavity is no longerrequired, rod 429 is retracted and blow pin 428 is raised clear ofmandrel 24. Double acting hydraulic cylinder 436 is activated pullingsplit blow mold half 408 away from split blow mold half 410. The blowncontainer which is still mounted to mandrel 24 will follow split blowmold half 408 for a short distance due to the action of follower rodsprings 606 and 606a. Once attaching apparatus 11 has traveled its fullextent, split blow mold half 408 continues to travel away from splitblow mold half 410 until a gap of sufficient dimension is achievedbetween the two split blow mold halves to permit free movement ofcontainers "B" when table 600 rotates to the next station.

It is to be understood that biaxial orientation can also be achieved bystretching of preform "P" with stretch rod 429 to achieve an axialstretch and then subsequently utilizing blow air to inflate the preformto conform to the cavity formed by split blow mold halves 410 and 408.

To achieve blow molding without biaxial orientation the proceduredescribed above is followed except that stretch rod 429 is left in theretracted position and is not activated at all. Thus blow fluid isintroduced through blow pin 428 without benefit of the axial stretchprovided by stretch rod 429.

Removal of bottles "B" from mandrels 24 and 24a is automaticallyachieved by the utilization of ejection station 20 which is shown inFIGS. 17 and 18. As can be seen ejection station 20 has a pair ofupstanding legs 520 and 520a. Joining these legs together at a pointnear their bottom are studs 522 and 522a which are bolted together asshown in FIG. 17. Mounted on studs 522 and 522a is double actinghydraulic cylinder 524. Double acting hydraulic cylinder 524 has its rodend connected to block 528. Providing more support for legs 520 and 520ais support member 526 which may be tied into a reinforced concretebulkhead or the like. As mentioned above, double acting hydrauliccylinder 524 is attached to block 528. Block 528 is slidably mounted onlegs 520 and 520a and will move upward and downward along these legs inresponse to the action of double acting hydraulic cylinder 524. A recessis provided in block 528 for holding a second double acting hydrauliccylinder 530. Second double acting hydraulic cylinder 530 is attached tobracket 547 which in turn is attached to slide 532. Second double actinghydraulic cylinder 530 will move slide 532 back and forth along ahorizontal plane. Slide 532 is trapezoidol in cross-section and fitswithin a trapezoidol cut in guide block 534. Guide block 534 thereforeassures proper horizontal motion of slide 532 and helps support slide532 throughout its travel. Attached to the top of slide 532 is knockoffplate 536. Knockoff plate 536 has two semicircular cuts made therein,542 and 542a, which allow knockoff plate 536 to move around the necks ofbottles "B" so that interference between knockoff plate 536 and thebottles "B" will occur when knockoff plate 536 is moved downward in avertical direction. Holding knockoff plate 536 to slide 532 isaccomplished by bolting attaching plate 537 over knockoff plate 536 andto slide 532.

To provide support for attaching mechanism 11 there are provided supportrollers 540 and 540a. Support roller 540a is rotatably carried by rollermount 538a while support roller 540 is carried by roller mount 538. Ascan be seen in FIGS. 17 and 18, support rollers 540a and 540 contactplate 608 to provide resistance to deflection of attaching member 11when knockoff plate 536 is lowered and brought into contact with bottles"B" to remove them from mandrels 24 and 24a.

In operation, bottles "B" are brought from blow molding station 18 to aposition in front of ejection station 20. Knockoff plate 536 is in aretracted and uppermost position. After bottles "B" are in properregistration with ejection station 20, second double acting hydrauliccylinder 530 is activated causing slide 532 to move away from table 600and thus bring knockoff plate 536 into position so that semicircularcuts 542a and 542 are about the neck portion of bottles "B."Consequently, double acting hydraulic cylinder 524 is activated bringingblock 528 downward causing knockoff plate 536 to likewise move downwardand engage bottles "B" and knock them from mandrels 24 and 24a. Afterbottles "B" have been so removed, hydraulic cylinder 524 is activatedthereby bringing knockoff plate 536 to its uppermost position. Alsosecond double acting hydraulic cylinder 530 is activated to causeknockoff plate 536 to be retracted.

With the ejection station 20 in this position, table 600 is rotated tothe next station which is injection molding station 12 so that theprocess can again be repeated.

Timing of the rotation of table 600 and the activation of the variousstations is accomplished by utilizing well known techniques which arefamiliar to those skilled in the art. Most systems will utilize acombination of electrical switches and photoelectric sensors asactivating and sensing hardware. The residence time spent at any onestation by attaching mechanism 11 will be determined by the timerequired by the slowest station. Generally speaking, the slowest stationis injection station 12, however, any of the other stations may requiremore time depending upon the particular requirements of the user of theapparatus of this invention. If injection molding station 12 requiresthe longest residence time, then the other stations will simply achievetheir designated purpose and will be waiting for rotation of table 600when the injection forming is accomplished.

What is claimed is:
 1. A process for injection blow molding hollowplastic bodies having an injection molded integral handle, said processcomprising:a. positioning a hollow preform carrier between an open splitinjection mold; b. closing said injection mold to form an injection moldcavity with a contiguous injection mold handle cavity and a preformcarrier cavity, said preform cavity enclosing at least a portion of saidpreform carrier upon said closing of said injection mold; c. inserting apreform pin through said preform carrier into said injection moldcavity; d. injecting thermoplastic material into the recess defined atleast partially by said injection mold cavity, said handle cavity andsaid preform pin to form a thermoplastic preform having a solidinjection molded handle; e. cooling said thermoplastic preform to atemperature at which it will maintain its basic shape when saidinjection mold is opened; f. withdrawing said preform pin from saidinjection mold cavity; g. opening said injection mold; h. moving saidinjection molded preform on said preform carrier from said splitinjection mold to a split blow mold having a handle cavity that islarger than said handle and having a neck cavity that has a largerdiameter at the point of juncture with said handle cavity than thediameter of said preform; and i. inflating said preform to the shapedefined by said blow mold cavity while allowing said handle to moveoutwardly in said handle cavity as the portion of said preform adjacentsaid neck cavity moves outwardly into contact with the walls of saidneck cavity.
 2. The process of claim 1 wherein between steps (g) and (h)said injection molded preform is temperature conditioned by eitherheating or cooling to bring the temperature of said preform to itsorientation temperature.
 3. The process of claim 1 whereincontemperaneous with said inflation said preform is biaxially stretchedso that biaxial orientation of said hollow plastic body is achieved.